Microwave displays E11 and beeps; keypad or touch controls may be unresponsive or behave erratically.

Safety first: Unplug the microwave before working on the control panel.

Step-by-step checks:

• 1. Inspect the control surface: Look for cracks in the touch glass, bubbling of the membrane, or signs of liquid spills around the keypad area.
• 2. Dry out moisture: If a recent spill occurred, leave the microwave unplugged with the door open for 24 hours to allow moisture to evaporate. Do not use heat sources directly on the panel.
• 3. Access keypad ribbon: Remove the control panel mounting screws and gently pull the panel forward. Locate the flat ribbon cable from the keypad to the control PCB.
• 4. Reseat the ribbon: Carefully disconnect and reconnect the ribbon cable, ensuring it is fully inserted and locked.
• 5. Test operation: Reassemble enough to safely power the unit and test the keypad. If E11 remains or keys still misbehave, the keypad membrane or touch assembly is likely defective.
• 6. Replace keypad: On some Grundig models, the keypad is integrated with the control panel fascia; on others, it is a separate membrane. Replace with the correct part and reassemble.

If a new keypad does not resolve E11, the control PCB may have a faulty keypad interface and should be replaced.